Question 257981
Cartesian coordinate system just means on graph paper where  there is an x and y.
You aren't real clear what you want. But based on the words you used I assume you want the slope form and standard form of an equation that has those two points.
Something to remember : There are an infinite number of equations that have those points.
given :(4,7) and (8,3)
formulas
standard form ax+by+c=0
slope form y=mx+b the b's are not the same!
In y=mx+b m is the slope and b is the y intercept (y when x=0)

To find the slope, we use (y-y)/(x-x)= m the slope
The slope is the gradient or incline or slant of the line.
our y's are 7 and 3
our x's are 4 and 8
Just keep the first and second in their place.
7-3/4-8=4/-4=-1 
our slope is -1 which means the line slants down from left to right.
Now we have y=-1x+b
y=-x+b
now pick either point and plug in the x and y
(4,7) x=4 y=7
7=-4+b
add 4 to both sides
11=b
now we have all the info needed.
y=-x+11 is the slope intercept form
when x=0 then  y=11
Now to get the standard form in the form ax+by+c=0

We want everything on one side
y=-x+11
add x and subtract 11
y+x-11=0
almost done
we need x first so we rearrange.
x+y-11=0 is the standard form

I don't know what "Label and intercept" means.
Label what and intercept what?
Do you need a graph too? and need to label the intercepts?
I suspect you copied something incorrectly.